Lorenz muther



(No Mdel.)

L. MUTHER. NEEDLE CLAMP FOR SEWING MACHINES.

No. 418,049. Patented Deo. 24, .1889.

wmvsssss; IW/w( UNITED STATES PATENT OFFICE.N

LORENZ MUTI-IER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE UNION SPECIAL SEWIING MACHINE COMPANY7 OF SAME PLACE.`

NEEDLE-CLAMP FOR SEW INGMACHINES.

SPECIFICATION forming part of Letters Patent No. 418,049, dated December 24, 1889.

Application filed April ll, 1889. Serial No. 306,869. (No model.)

To all whom t may concern-.-

Be it known that I, LORENZ MUTHER, of Chicago, county of Cook, and State of Illinois, have invented an Improvement in Needle- 5 Bars for Sewing-Machines, of which the following is a specification.

My invention relates to 'needleclainps for sewing-machines; and it consists of certain improvements which are fully set forth in the 1o following specification and shown in the accompanying drawings, which form a part thereof.

More particularly my invention relates to that class of needle-clamps which carry two I needles for double rows of stitching; and it consists of improvements in the clamping devices by which the needles are held to the bar.

It has been one of the greatest difficulties met with in sewing-machines employing two 2o needles to construct a needle-clamp suited to different sizes of needles, so that in all cases the needles will be firmly clamped or secured within the bar in proper relation to each other and also to the shuttle or looper of the 2 5 sewing-machine. Bars which are suited to needles of one size are not usually suited to needles of another size without some change or adjustment in the clamping devices of the bar.

It is the object of` my invention to overcome this diflicultyand to construct a needleclamp suited to different sizes of needles, so that the needles may easily be changed from one size to another, and will in all instances 3 5 be firmly held or clampedwithin the bar and in proper relation to each other. This object I accomplish by means of a clampingpiece within the needle-bar adapted to be forced upon the Shanks of the needles to 4o force their flattened sides against each other and to secure them irmly within the bar, and also in proper relation to the shuttle or looper.

The nature and operation of these devices are more fully explained in the description of the drawings, in which-- Figure l is a side elevation of a needle-bar embodying the principles of my invention. Fig. 2 is a side view of the same on the line 5o wx of Fig. l, with part in section.e Fig. 3 is a horizont-al sectional view on the line y y of Fig. l. Fig. 4 is an inverted planview of my improved needle-bar on an enlarged scale; and Fig. 5 is a horizontal sectional view illustrating a modified arrangementof the clamping devices.

A is a needle-bar proper, which is provided on its lowerend with a groove a, preferably U-shaped in cross-section, within which the shanks b of the needles B are placed. These 6o shanks b are iattened or cut away upon one side, and these iiattened sides are placed in contact with each other. These sides of the shanks are more or less cut away or flattened according to the size of the needle, as it is necessary to bring the points of the finer needles closer together than those of the coarser neeedles.

Cis a clamping-piece adapted to fit within the U-shaped groove a, and having inclined 7o inner surfaces.

D is a collar loosely secured to the end of the needle-bar A by means of a pin E, which` extends also through a hole in the clainpingpiece C, securing it to the needle-bar. F is a screw extending through the collar D, and adapted to press upon the clamping piece or die C, to force it more deeply within the groove a., The Shanks b of the needles are inserted within the groove a, having their at 8o sides in contact, and, as heretofore described, the clamping-piece C is now forced inwardly by tightening the screw F, and the inner inclined sides of thisclamping-piece press upon the Shanks h of the needles, on the principle of a wedge, forcing the'lattened sides tightly against each other, and clamping the shanks Within the needle-bar. If now it is desired to substitute needlesof a smaller' size for. those first used, the screw F is loosened and 9o the needles B B are taken out and replaced by a second pair of smaller needles,which, as heretofore explained, have their shanks more cut away or flattened, so as to bring the points of the needles nearer together. The

clamp C is now tightened up and extends a greater distance into the groove a, owing to the smaller space occupied by the two shanks b b, in.V consequence of the increase in the amount cut away. The inclined surfaces of roo the clamping-piece Opress upon these shanks and force them together in a similar manner to that above described.

The operation of the clamping device with my preferred. shape of groove in the needlebar and with needles of different sizes is illustrated in Fig. 4, in which the larger needles and the first position of the clamping-piece C are shown in full lines and the smaller needles and the second position of the clampingpieee in dotted lines. The inner surface of the U-shaped groove a may be made curved, as shown in this figure, so that the points ofthe needles will always be keptthe same distance from the line of the movement of the shuttle or looper. (Shown in dotted lines in Fig. 4.) The inclined surface of the clamping-piece C always presses upon the shanks h, and as the size of the shanks is decreased for smalleri needles, owing to the larger amount which is cut away, this inclined surface presses upon the shanks at points higher up or nearer the middle, but, owing to the inclination,always in such a manner that the lines of the force exerted at these two points of 'contact tend to meet, and consequently have the effect of forcing the flat sides of the shanks against each other.

The object and effect of formingthe groove d with its inner surface curved are shown in Fig. 4. As the size of the needles is decreased and the shanks are more an'd more cut away, the space occupied by the shanks is diminished and the shanks sink deeper into the curve of the groove a', or farther in toward the line of motion of the shuttle or looper of the machine, sufficiently to compensate for the actual difference in size of the needles, so that v the distance from the plane in which the edges of the needles move to the line of motion of the shuttleor looper will be exactly the same no matter what the size of the needles may be. The inclined grooves in the clampingpiece and needle-bar may, if desired,be curved or V-shaped.

It is apparent that instead of forcing the clamping-piece C down upon the shanks of the needles by the action of screw directly upon the clamping-piece the screw may press against the needle bar to draw the collar down upon the clamps, as shown in Fig. 5.

Vhile I prefer the detailsiof construction here shown, it is apparent that they may be modified without departing from the principles of my invention.

I-Iaving now described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. The combination of a needle-bar having a groove on its end forming a socket for the shanks of the needles, two needles having their shanks in contact with each other within shanks in contact within said groove, in combination with a clamping-piece carried by said needle-bar and having inclined inner surfaces, and means to press said clamping-piece into said grooveto clamp the shanks of the needles therein and press their fiattened sides together.

3. A needle-bar having a groove at its end, two needles having the flattened sides of their shanks in contact within said groove, in combination with a clamping-piece carried by said needle-bar and having inclined inner surfaces, and an adjustable pressure-point to press upon said clamping-piece to force it into said groove to clamp the shanks of the needles therein and press their flattened sides together.

4. A needle-bar having a groove at its end formed with its lbase curved, two needles having the flattened sides of their shanks in contact within said groove, in combination with a clamping-piece carried by said needle-bar, and means to press said clamping-piece into said groove to clamp the shanks of the needles therein and press their flattened sides together.

5. The needle bar A, provided with the groove ct at one end, in combination with the clamping-piece C, carried by said bar and fit- IOO IIO 

